Roller mills having a displacing mechanism for skewing at least one milling roller relative to the other have already been proposed occasionally in the literature in order to avoid the necessity of cambering or crowning the rollers over their length. Examples of such constructions may be found in the French Pat. Nos. 1,028,098 and 1,273,350 as well as in the U.S. Pat. No. 2,762,295, whereas with respect to rollers with a real camber or crown, it is referred to U.S. Pat. Nos. 3,078,747, 3,097,591 or 3,138,089.
Mostly, roller mills with a skew are operated with a predetermined desired pressure corresponding to a predetermined skew of the rotational axis or, in roller mills without such a skewing device, with a predetermined camber or crown. Therefore, the known roller mills according to the above-mentioned references were only provided with a manual adjusting device for the skew whereby the respective foreman could adjust the angle of the skew by means of a screw-socket wrench.
Of course, this is inconvenient in roller mills in which the pressure is adjustable, e.g. in calenders for textile material. Thus, for such an application, it has been proposed in the U.S. Pat. No. 3,240,148 to mount on a common shaft either a pressure eccentric for manually adjusting the roller pressure and a displacing eccentric for skewing the axis of one roller. It will be understood that such a construction will only be applicable for relative small operational pressures, as may occur in textile calenders. However, if--for controlling purposes or for adjusting the mill to grind different products--the pressure has to be changed in such roller mills where pressures of several hundred kilograms or even of several tons are applied, the prior solution is no longer feasible.